16层螺旋CT肠系膜上动、静脉成像诊断小肠扭转的前瞻性研究

目的前瞻性研究肠系膜上动、静脉CT血管造影（CTA）对小肠扭转（SBV）的诊断价值。资料与方法使用16层螺旋CT对16例经临床及CT平扫拟诊SBV的患者行肠系膜上动、静脉CTA检查。肠系膜上动、静脉采用最大密度投影（MIP）及容积再现（VR）重组。以手术或随访作为参考标准，分析CTA对SBV的诊断价值。结果16例中，有2例表现为肠系膜上静脉主干远段的反折，其中1例见肠系膜上动脉分支的反折；3例表现为肠系膜上静脉不同属支的反折，其中1例见肠系膜上静脉主干的轴向扭曲；走行异常的血管均与扩张小肠袢位置相吻合。10例CTA诊断为非SBV。5例SBV均经手术证实，CTA诊断的敏感度、特异度、阳性预测值、阴性预测值、准确性分别为100％（5／5）、90．9％（10／11）、83、3％（5／6）、100％（10／10）、93．8％（15／16）。结论肠系膜上动、静脉CTA是诊断SBV的有价值的检查技术，肠系膜上静脉或其属支的反折为SBV主要的CTA表现。

Prospective Study of CT Angiography of Superior Mesenteric Artery and Vein Using 16-slice Helical CT in Diagnosing Small Bowel Volvulus

Objective To prospectively assess the accuracy of CT angiography (CTA) of superior mesenteric artery (SMA) and superior mesenteric vein (SMV) in diagnosing small bowel volvulus (SBV). Materials and Methods 16 patients suspected of SBV according to clinical and plain CT manifestations were examined with CTA of SMA and SMV using Siemens 16-slice helical CT. Maximum intensity projection (MIP) and volume rendering (VR) images of SMA and SMV were acquired. The accuracy of CTA in diagnosing SBV was evaluated and compared with surgery or follow-up as the standards of reference. Results Tortuosity of distal SMV was seen in 2 cases and tortuous SMA branches was seen in 1 case. Tortuosity of various tributaries of SMV was seen in other 3 cases and axial torsion of SMV observed in 1 case. There was a correlation between abnormal vascular and location of dilated small bowel loops. SBV was confirmed in 5 patients by surgery. In the diagnosis of SBV, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 100%, 90.9%, 83.3%, 100%, and 93.8%, respectively, for CTA of SMA and SMV. Conclusion CTA of SMV and SMA is a valuable method for the diagnosis of SBV, tortuosity of SMV or its tributaries is the main CTA findings.